(i) In fig. 4.70, if , find the value of x.

Diagonal of trapezium divide each other proportiona

AO/OC=BO/OD


4/4X-2=x+1/2x+4


4x2-2x+4x-2=8x+16


4x2+2x-2-8x-16=0


4x2-6x-18=0


2(2x2-3x-9)=0


2x2-3x-9=0


2x2-6x+3x-9=0


2x(x-3)+3(x-3)=0


(x-3)(2x+3)=0


x-3=0


x=3


or,2x+3=0


2x=-3


x= -3/2


x=-3/2 is not possible


So x=3


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